function readFileFirefox(fileBrowser) {

    var fileName = fileBrowser.value;
    var file = Components.classes["@mozilla.org/file/local;1"]
            .createInstance(Components.interfaces.nsILocalFile);
    try {
        file.initWithPath(fileName.replace(/\//g, "\\\\"));
    } catch (e) {
        if (e.result != Components.results.NS_ERROR_FILE_UNRECOGNIZED_PATH)
            alert('路径错误2!');
        return;
    }

    if (file.exists() == false) {
        alert("File '" + fileName + "' not found.");
        return;
    }
    return file.path;
}